Survey Research Among Neurosurgeons: A Bibliometric Review of the Characteristics, Quality, and Citation Predictors of the Top 50 Most-Influential Publications in the Neurosurgical Literature

Survey research enables the gathering of information on individual perspectives in a large cohort. It can be epidemiological, attitude or knowledge focussed. Assessment of survey studies sampling neurosurgeons is currently lacking in the literature. This study aimed to highlight the characteristics, quality, and citation predictors of the most influential survey research studies published in the neurosurgical literature. Using PubMed and Google Scholar, the 50 most cited survey research publications were identified and reviewed. Data relating to the characteristics of the articles, participants and questionnaires were retrieved. The studies’ quality and citation patterns were assessed. The median articles' age and publishing journal impact factor (IF) were 15.5 years and 2.82, respectively. Thirty-two (64%) articles were first authored by researchers from the USA while 28(56%) studies were focussed on specific disease management. The median number of participants and response rates were 222 and 51%, respectively. A full version of the questionnaire was provided in 18 (36%) articles. Only four (8%) articles reported validation of the questionnaire. The overall quality of reporting of the surveys was considered fair (based on good grading in five parameters, fair grading in one parameter, and poor grading in four parameters). The median citation number was 111. The citation analysis showed that the participant number, article age (≥15.5 years), and questionnaire category (surgical complications) were significant predictors of citation numbers. The citation rates were not influenced by the response rates or the journal’s IF. In conclusion, high-impact survey publications in the neurosurgical literature were moderately cited and of fair quality. Their citation numbers were not affected by response rates but were positively influenced by the publication age, number of participants, and by novel data or the questions raised in the survey category. Surveys are valuable forms of research that require extensive planning, time, and effort in order to produce meaningful results. Increasing awareness of the factors that could affect citations may be useful to those who wish to undertake survey research


Introduction And Background
Surveys are research methods in which information is typically collected by asking a subset of people questions on a specific topic and generalizing the results to a larger population [1,2].They are widely used in many specialities, but mostly in public health, politics, ethics, and education [1,2].Surveys are particularly valuable in studies that need patients or clinicians to self-report their experiences, satisfaction, and attitudes towards concepts that are difficult to measure using alternative approaches [1,2].They are useful at the beginning of exploratory studies and can be the basis for going on to the next levels of evidence [1,2].Surveys are generally considered low-cost research tools that are easy to apply [2].However, to be reliable, they require good planning and construction as well as clear reporting so readers can judge the strengths and weaknesses of the study as well as the generalizability of the results [1][2][3].The number of surveys published in the medical literature has increased in recent years [1,3].Furthermore, assessing the quality of survey research is a topic of current interest in the literature [1][2][3][4][5].Most of the published reviews stated that the quality of the reporting of surveys was either poor [1,3] or moderate [2,4,5].The issues raised included weak designs of questionnaires, lack of validation and reliability tests of the instruments used, low response rates, shortage of information on the representativeness of the samples, and deficiency of explanations on how missing data was handled [1][2][3][4][5].Recent guidelines for clinical survey research emphasized the need to reduce potential sources of bias by using validated questions, pre-testing the questionnaires, and enhancing response rates by using incentives or reminders [2,4].
The number of citations a published article receives is arguably one of the most important indicators of its impact and clinical weight.Identification of the predictors of citations is valuable for researchers to enhance the impact of their work.It is a topic that has been the subject of numerous studies in recent years.Most publications on the matter concentrated on determining the predictors of citations in articles relating to certain medical specialties, disease processes, peer-reviewed journals, or a specific research methodology [6,7].Analysis of the citation patterns of survey research remains limited in the literature.Furthermore, assessments of survey studies sampling neurosurgeons are also lacking.The purpose of this study is to identify and review the most-cited survey research studies that were published in the neurosurgical literature.The review aimed to highlight the characteristics and quality of survey research studies that sampled neurosurgeons and determine the factors that affect the citation numbers of the top 50 mostinfluential studies on the subject.

Search Strategy
No ethical approval was necessary by our institutions as the study was based on data obtained from openaccess sources.The PubMed database was searched on 1st October 2023 for suitable articles using the following combinations: [Title] "survey" AND [Journal] "individual neurosurgical and spine journals by name".The list of journals searched, and the number of screened articles is shown in Table 1.The search yielded a total of 921 publications in 30 neurosurgical and spine journals which will be referred to as neurosurgical journals in this study.Using Google Scholar, the citation numbers for all screened articles were documented.In view of the regular changes in the citation numbers, the findings on a single day (15th December 2023) were documented and used for analysis.The 50 most-cited articles were identified and chosen for this review.The selection was limited to surveys published in the neurosurgical journals in which the participants were surgeons, surgical residents or a combination of surgeons and non-surgeons.We excluded studies in which all participants were non-surgeons and articles that did not provide an adequate description of the survey process or other pertinent data.The selected articles are referred to as "most cited", or "most influential", or as "high-impact survey research articles sampling neurosurgeons" interchangeably in this review.

Analysis of Characteristics
Using the full articles, relevant information relating to each of the selected studies was collected by two of the authors independently and any discrepancies were resolved by consensus.Missing data was referred to as not available (NA).The extracted data was grouped into: Articles' characteristics: publication year, publishing journal, its impact factor (IF), number of authors, number of centres, number of specialties, number of countries and first authors' countries.The journals' IF data was obtained from an online source [8].Participants' characteristics: their number, population (whether individuals, groups, or centres), selection method (whether from affiliation to associations or workgroups, medical meeting attendees, panel of experts or random individuals or hospitals), response rates, specialties, and worldwide regions.Questionnaires' characteristics: number of items on the questionnaire, subspecialties, categories (whether specific disease management, training and career, surgical complications, or methods and techniques) and the individual topics.

Analysis of Quality
The quality assessment was comparable to others [1][2][3][4][5] and was based on whether several parameters were clearly reported in the articles.These were: study population, sample selection methods, sample size, response rate, incomplete response rate, non-responders characteristics, the full version of the questionnaire, number of items on the questionnaire, and whether the questionnaire was validated or pretested.The quality of reporting of each parameter in ≥ 66% of articles was graded as good, in 34%-65% of articles was graded as fair and in ≤ 33% of articles was graded as poor.The quality grading was determined by two of the authors independently and any discrepancies were resolved by consensus.

Analysis of Citation Predictors
The citation predictors assessment was carried out by correlating the citation numbers for the selected studies with the various article, participant, and questionnaire characteristics.The correlation testing was done by calculating the Pearson correlation coefficient (R) using the Social Sciences Statistics website [9], and significance was determined when p ≤ 0.05.A secondary citation predictors analysis was carried out by comparing the mean citation numbers [± standard deviation (SD)] between the following subgroups: articles' ages [≥15.5 versus (vs.) <15.5 years], journals' IF (≥2.82 vs. <2.82),number of authors (>4 vs. ≤4), number of centres (1 vs. >1), number of specialties (1 vs. >1), number of countries (1 vs. >1), first authors' countries (USA vs. others), participants' numbers (≥222 vs. <222), participants' response rates (≥51% vs. <51%), participants' specialties (general neurosurgeons vs. others), participants' selections (associations/groups vs. others), participants' worldwide regions (North America vs. others), questionnaires' number of items (≥12 vs. <12), questionnaires' subspecialties (spine vs. others), questionnaires' categories (management/ training and career/ complications vs. others).The median was taken as a cut-off point in the numerical parameters The statistical analysis was carried out by calculating the mean difference (MD) using the MedCalc website [10].Significance was determined when p ≤ 0.05.

Results
The 50 most-cited survey research studies sampling neurosurgeons are summarised in Table 2 .The studies' characteristics were as follows:

FIGURE 4: The distribution of the 50 high-impact articles according to the surveys' subspecialties
The distribution of the articles according to the questionnaires' categories is shown in Figure 5.These were specific disease management: 28 (56%), training and career: nine (18%), surgical complications: eight (16%), and methods and techniques: five (10%).

FIGURE 5: The distribution of the 50 high impact articles according to the surveys' categories
The most common survey topics among the 50 most-cited articles were residency training-related matters (five articles).These were duty hours reform [26], burnout and career dissatisfaction [35], the role of laboratory dissection in residency training [52], quality of residency training [59], and the residency selection process [60].The other common topics were Chiari and syringomyelia (four articles) [15,18,23,45], the use of prednisolone in spinal cord injury (two articles) [25,50], vertebral artery injury in cervical spine surgery (two articles) [12,14], deep brain stimulation procedures (two articles) [31,43], complications of lateral interbody fusion (two articles) [24,42], and Moyamoya disease (two articles) [48,51].A full list of the topics is shown in Table 2.

Study Citation Predictors
The median (range) and mean (±SD) article citation numbers were 110.5 (60-1345) and 155.8 (± 194.6) cites, respectively.Table 3 and Table 4 summarize the correlation and secondary analysis findings between the citation numbers and the various characteristics of the selected articles.The correlation analysis showed a significant association between citation numbers and participant number (p=0.0261).The secondary analysis demonstrated significantly higher mean citation numbers in articles aged ≥15.

Discussion
Surveys are popular among clinical researchers, including neurosurgeons.The challenges of planning, designing, and implementing questionnaire surveys are often underestimated.A good survey requires an important topic, an appropriate sample size, an acceptable tool, a good response rate, precise results, and conclusions consistent with findings [61].A quality survey should have the smallest possible number of high-quality essential items that will interest the population.It should also provide reproducible results (reliable) and measure what it is supposed to measure (valid) [61].Surveys can be problematic as ensuring impartial, voluntary participation is not always easy.A large questionnaire with many nondirected questions not only deters potential respondents but also makes it difficult to evaluate validity [61].Badgering respondents is quite likely to provoke an untruthful response, simply to meet an obligation.The participants' responses to the questions can fluctuate due to multiple confounding reasons.The questions may be leading, unclear, or display an inherent bias of the researcher [62,63].Surveys within small communities come with added validity drawbacks.Unlike patient or public surveys that are normally anonymous, surveys among colleagues mean that the respondents and researchers are known to each other and some responses may occur simply with the aim of pleasing the researcher rather than through a true intention to participate [62,63].All survey measures, whether quantitative or qualitative, are subject to error.The four most common areas of survey errors are coverage (selected sample is different from the surveyed population), sampling (sample size miscalculated or not truly random), measurement (answer is inaccurate or imprecise due to poor question), and non-response (responders are different for the nonresponders on the question of interest) [62,63].
The reporting of the research question, study population and sample selection was considered good in all articles which is in agreement with others [2,5,64].The majority of participants (54%) were members of associations or groups which is not surprising as it is common for surveys to sample readily available groups (convenience sampling) [3,65].Some reviewers may have applied stricter criteria and indicated that survey reporting was weak in the description of the study population in 24% [2], the eligibility criteria for the participants in 35% [3] and the characteristics of the respondents in 10% [3].
The sample size was documented in 88% of our articles which is at the upper limit of the range of 53%-88% stated for the reporting of the sample size by other reviews [2,5].The median response rate was 51% which is within the range of 37%-66% recorded by others [4,64].None of our articles mentioned whether there were incomplete responses.It has been observed that the reporting of missing data in survey research has improved over the years [3].Nevertheless, it remains a weak spot that was addressed in only 1.3% to 27% of surveys [1,2,4,5,65].Only 4% of our articles provided data relating to the characteristics of the nonrespondents.Reporting descriptions of the non-respondents is another weak point in survey research that was tackled in only 7% to 11% of studies [2,4,5].None of our articles reported the use of incentives or reminders.Incentives were used in 7% to 30% of studies [2][3][4][5] while reminders were used in 43% to 73% of surveys [3,4,65].A recent study however concluded that the use of reminders was not associated with higher response rates [4].
The full version of the questionnaire was provided in 36% of our articles which is within the range of 13% to 61% stated in the literature [2,5,65,67].Only 8% of studies reported that the questionnaires were validated.
In the literature, the use of validated instruments has been reported in 19% to 63% of surveys [1][2][3][4][5]64] while the use of previously published questionnaires was reported in 7%-50% of studies [2,5,65].Only 2% of our articles reported that the questionnaires were pretested which is relatively low compared to the range 26%-76% mentioned by others [2,4,64,65].The majority of questionnaires in our articles were disease-specificmanagement-related (56%), which is in agreement with others [3,65].Some authors reported that the majority of the questionnaires were current practice [66], opinion-related [67], or education [64].This could be related to differences in the categorization of the focus of the survey between the various reports.
The median citation number for the 50 most-cited survey research studies among neurosurgeons was 111 cites.This was lower than the citation number for higher levels of evidence research studies such as the top 100 glioblastoma trials (median 349 citations) [7].Variation in citation rates according to study design and subject is well recognized in the literature [68][69][70].We found that the number of participants and the age of the publication (≥15.5) were significant predictors of citation numbers.We also observed that a research question related to specific complications in a survey was also a positive predictor of citation rates.This supports the observation that the novel data or the questions raised in the survey are an important predictor of citations [4].In this review and comparable to others, we did not establish a positive link between citation rates and the participants' response rates [4] or the publishing journal's IF [5].Furthermore, none of the other parameters tested in this review affected citations.These were the number of authors, centers, specialities, countries, and the first author's country, participants' specialty, participants' selection, participants' worldwide regions, surveys' number of items, and survey subspecialties.

Limitations
There are several limitations to this study which include the general limitations of bibliometric studies.The study relied on the precision of online search engines PubMed and Google Scholar.The review did not include survey research studies among neurosurgeons that were published outside the neurosurgical literature.The presence of a good number of neurosurgical journals in one country (USA) could be a possible source of bias in both publications and citations depending on the degree of network between authors, reviewers and editors within that country.The selection of the 50 most-cited studies was based on their total citations at a certain point which was likely to change relatively quickly.This could have influenced the inclusion or exclusion of a few of the lower-impact surveys.The wide duration from publication may have affected the citations of older studies.The changing trends in the reporting of surveys over the years were not addressed.There may have been errors in the data collection.There may have been discrepancies in the grouping of articles into the various categories.The quality assessment may have not been comprehensive.Not providing the full version of the questionnaire may have been due to editorial restrictions.The review did not look at mode of administration of the questionnaires.Defining the specialty and affiliation based on the first author may not reflect all authors of multi-disciplinary papers.The impact of articles using the Altmetric score of news media and social media mentions was not done.

Conclusions
High-impact survey publications in the neurosurgical literature were relatively old, moderately cited, and of fair quality.The majority of articles were first authored by researchers from the USA and focussed on specific disease management.Their citation numbers were not affected by response rates but were positively influenced by the publication's age, number of participants, and novel data or the questions raised in the survey category.Surveys are valuable forms of research that require extensive planning, time, and effort in order to produce meaningful results.Increasing awareness of the factors that could affect citations may be useful to those who wish to undertake survey research.

FIGURE 3 :
FIGURE 3: The distribution of the 50 high-impact articles according to the participants' worldwide regions
5 years (p=0.0236)and studies in which the surveys' categories were complications-related (P=0.0016).None of the other parameters, in particular the response rates and the journals IF, reached significance

TABLE 3 : Summary of the primary analysis correlation findings between the citation numbers and the various characteristics for the 50 most-cited survey research publications in the neurosurgical literature
2024 Jamjoom et al.Cureus 16(7): e64785.DOI 10.7759/cureus.64785

TABLE 4 : Summary of the secondary analysis mean difference findings between the citation numbers and the various characteristics for the 50 most-cited survey research publications in the neurosurgical literature
*Denotes significance